Ion implantation technology, as a doping technology of a semiconductor material, has advantages of low-temperature doping, easy masking, precise dosage control and high uniformity, can be used in a plurality of processes such as source/drain electrode doping, channel doping, lightly-doped drain doping, and can make a manufactured semiconductor device have the properties such as fast speed, low power consumption, good stability, high yield and so on. In different ion implantation technologies, conditions such as required energy dosage and the like are different, and doping is performed in a designated region during ion implantation, and the rest positions need to be masked (shielded) by a blocking layer such as a photoresist layer. The blocking abilities of photoresist blocking layers with different thicknesses for ion implantation are different, ions can easily pass through a blocking layer of a too small thickness, while for a photoresist blocking layer of a too large thickness, it is hard to control the key feature during a photolithograph process, and thus it is required to select a photoresist blocking layer with a suitable thickness during implantation.
A conventional method of determining the blocking ability of a photoresist blocking layer comprises the following steps: providing a plurality of testing silicon slices; coating photoresist layers with different thicknesses on different testing silicon slices; measuring the thickness of the photoresist of each silicon slice; implanting ions with a certain energy into the abovementioned silicon slices coated with the photoresist layers with different thicknesses; removing the photoresist layers of the silicon slices; and using a secondary ion mass spectrometry to test the silicon slices to obtain ion implantation amounts of all the silicon slices, and when an ion amount is in an allowed range, the thickness of the photoresist blocking layer, to which the silicon slice with this ion amount corresponds, is considered to be suitable.